1321 lines
38 KiB
C++
1321 lines
38 KiB
C++
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// This code is in the public domain -- castano@gmail.com
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#include "nvmesh.h" // pch
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#include "AtlasBuilder.h"
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#include "Util.h"
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#include "nvmesh/halfedge/Mesh.h"
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#include "nvmesh/halfedge/Face.h"
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#include "nvmesh/halfedge/Vertex.h"
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#include "nvmath/Matrix.inl"
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#include "nvmath/Vector.inl"
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//#include "nvcore/IntroSort.h"
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#include "nvcore/Array.inl"
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#include <algorithm> // std::sort
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#include <float.h> // FLT_MAX
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#include <limits.h> // UINT_MAX
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using namespace nv;
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namespace
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{
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// Dummy implementation of a priority queue using sort at insertion.
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// - Insertion is o(n)
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// - Smallest element goes at the end, so that popping it is o(1).
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// - Resorting is n*log(n)
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// @@ Number of elements in the queue is usually small, and we'd have to rebalance often. I'm not sure it's worth implementing a heap.
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// @@ Searcing at removal would remove the need for sorting when priorities change.
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struct PriorityQueue
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{
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PriorityQueue(uint size = UINT_MAX) : maxSize(size) {}
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void push(float priority, uint face) {
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uint i = 0;
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const uint count = pairs.count();
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for (; i < count; i++) {
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if (pairs[i].priority > priority) break;
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}
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Pair p = { priority, face };
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pairs.insertAt(i, p);
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if (pairs.count() > maxSize) {
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pairs.removeAt(0);
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}
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}
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// push face out of order, to be sorted later.
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void push(uint face) {
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Pair p = { 0.0f, face };
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pairs.append(p);
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}
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uint pop() {
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uint f = pairs.back().face;
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pairs.pop_back();
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return f;
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}
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void sort() {
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//nv::sort(pairs); // @@ My intro sort appears to be much slower than it should!
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std::sort(pairs.buffer(), pairs.buffer() + pairs.count());
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}
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void clear() {
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pairs.clear();
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}
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uint count() const { return pairs.count(); }
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float firstPriority() const { return pairs.back().priority; }
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const uint maxSize;
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struct Pair {
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bool operator <(const Pair & p) const { return priority > p.priority; } // !! Sort in inverse priority order!
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float priority;
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uint face;
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};
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Array<Pair> pairs;
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};
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static bool isNormalSeam(const HalfEdge::Edge * edge) {
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return (edge->vertex->nor != edge->pair->next->vertex->nor || edge->next->vertex->nor != edge->pair->vertex->nor);
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}
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static bool isTextureSeam(const HalfEdge::Edge * edge) {
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return (edge->vertex->tex != edge->pair->next->vertex->tex || edge->next->vertex->tex != edge->pair->vertex->tex);
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}
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} // namespace
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struct nv::ChartBuildData
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{
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ChartBuildData(int id) : id(id) {
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planeNormal = Vector3(0);
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centroid = Vector3(0);
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coneAxis = Vector3(0);
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coneAngle = 0;
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area = 0;
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boundaryLength = 0;
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normalSum = Vector3(0);
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centroidSum = Vector3(0);
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}
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int id;
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// Proxy info:
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Vector3 planeNormal;
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Vector3 centroid;
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Vector3 coneAxis;
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float coneAngle;
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float area;
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float boundaryLength;
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Vector3 normalSum;
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Vector3 centroidSum;
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Array<uint> seeds; // @@ These could be a pointers to the HalfEdge faces directly.
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Array<uint> faces;
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PriorityQueue candidates;
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};
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AtlasBuilder::AtlasBuilder(const HalfEdge::Mesh * m) : mesh(m), facesLeft(m->faceCount())
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{
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const uint faceCount = m->faceCount();
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faceChartArray.resize(faceCount, -1);
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faceCandidateArray.resize(faceCount, -1);
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// @@ Floyd for the whole mesh is too slow. We could compute floyd progressively per patch as the patch grows. We need a better solution to compute most central faces.
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//computeShortestPaths();
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// Precompute edge lengths and face areas.
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uint edgeCount = m->edgeCount();
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edgeLengths.resize(edgeCount);
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for (uint i = 0; i < edgeCount; i++) {
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uint id = m->edgeAt(i)->id;
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nvDebugCheck(id / 2 == i);
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edgeLengths[i] = m->edgeAt(i)->length();
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}
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faceAreas.resize(faceCount);
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for (uint i = 0; i < faceCount; i++) {
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faceAreas[i] = m->faceAt(i)->area();
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}
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}
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AtlasBuilder::~AtlasBuilder()
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{
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const uint chartCount = chartArray.count();
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for (uint i = 0; i < chartCount; i++)
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{
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delete chartArray[i];
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}
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}
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void AtlasBuilder::markUnchartedFaces(const Array<uint> & unchartedFaces)
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{
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const uint unchartedFaceCount = unchartedFaces.count();
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for (uint i = 0; i < unchartedFaceCount; i++){
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uint f = unchartedFaces[i];
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faceChartArray[f] = -2;
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//faceCandidateArray[f] = -2; // @@ ?
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removeCandidate(f);
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}
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nvDebugCheck(facesLeft >= unchartedFaceCount);
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facesLeft -= unchartedFaceCount;
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}
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void AtlasBuilder::computeShortestPaths()
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{
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const uint faceCount = mesh->faceCount();
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shortestPaths.resize(faceCount*faceCount, FLT_MAX);
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// Fill edges:
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for (uint i = 0; i < faceCount; i++)
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{
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shortestPaths[i*faceCount + i] = 0.0f;
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const HalfEdge::Face * face_i = mesh->faceAt(i);
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Vector3 centroid_i = face_i->centroid();
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for (HalfEdge::Face::ConstEdgeIterator it(face_i->edges()); !it.isDone(); it.advance())
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{
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const HalfEdge::Edge * edge = it.current();
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if (!edge->isBoundary())
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{
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const HalfEdge::Face * face_j = edge->pair->face;
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uint j = face_j->id;
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Vector3 centroid_j = face_j->centroid();
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shortestPaths[i*faceCount + j] = shortestPaths[j*faceCount + i] = length(centroid_i - centroid_j);
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}
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}
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}
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// Use Floyd-Warshall algorithm to compute all paths:
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for (uint k = 0; k < faceCount; k++)
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{
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for (uint i = 0; i < faceCount; i++)
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{
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for (uint j = 0; j < faceCount; j++)
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{
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shortestPaths[i*faceCount + j] = min(shortestPaths[i*faceCount + j], shortestPaths[i*faceCount + k]+shortestPaths[k*faceCount + j]);
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}
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}
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}
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}
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void AtlasBuilder::placeSeeds(float threshold, uint maxSeedCount)
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{
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// Instead of using a predefiened number of seeds:
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// - Add seeds one by one, growing chart until a certain treshold.
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// - Undo charts and restart growing process.
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// @@ How can we give preference to faces far from sharp features as in the LSCM paper?
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// - those points can be found using a simple flood filling algorithm.
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// - how do we weight the probabilities?
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for (uint i = 0; i < maxSeedCount; i++)
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{
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if (facesLeft == 0) {
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// No faces left, stop creating seeds.
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break;
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}
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createRandomChart(threshold);
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}
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}
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void AtlasBuilder::createRandomChart(float threshold)
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{
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ChartBuildData * chart = new ChartBuildData(chartArray.count());
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chartArray.append(chart);
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// Pick random face that is not used by any chart yet.
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uint randomFaceIdx = rand.getRange(facesLeft - 1);
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uint i = 0;
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for (uint f = 0; f != randomFaceIdx; f++, i++)
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{
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while (faceChartArray[i] != -1) i++;
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}
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while (faceChartArray[i] != -1) i++;
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chart->seeds.append(i);
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addFaceToChart(chart, i, true);
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// Grow the chart as much as possible within the given threshold.
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growChart(chart, threshold * 0.5f, facesLeft);
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//growCharts(threshold - threshold * 0.75f / chartCount(), facesLeft);
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}
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void AtlasBuilder::addFaceToChart(ChartBuildData * chart, uint f, bool recomputeProxy)
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{
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// Add face to chart.
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chart->faces.append(f);
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nvDebugCheck(faceChartArray[f] == -1);
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faceChartArray[f] = chart->id;
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facesLeft--;
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// Update area and boundary length.
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chart->area = evaluateChartArea(chart, f);
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chart->boundaryLength = evaluateBoundaryLength(chart, f);
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chart->normalSum = evaluateChartNormalSum(chart, f);
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chart->centroidSum = evaluateChartCentroidSum(chart, f);
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if (recomputeProxy) {
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// Update proxy and candidate's priorities.
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updateProxy(chart);
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}
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// Update candidates.
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removeCandidate(f);
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updateCandidates(chart, f);
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updatePriorities(chart);
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}
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// @@ Get N best candidates in one pass.
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const AtlasBuilder::Candidate & AtlasBuilder::getBestCandidate() const
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{
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uint best = 0;
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float bestCandidateMetric = FLT_MAX;
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const uint candidateCount = candidateArray.count();
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nvCheck(candidateCount > 0);
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for (uint i = 0; i < candidateCount; i++)
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{
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const Candidate & candidate = candidateArray[i];
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if (candidate.metric < bestCandidateMetric) {
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bestCandidateMetric = candidate.metric;
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best = i;
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}
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}
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return candidateArray[best];
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}
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// Returns true if any of the charts can grow more.
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bool AtlasBuilder::growCharts(float threshold, uint faceCount)
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{
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#if 1 // Using one global list.
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faceCount = min(faceCount, facesLeft);
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for (uint i = 0; i < faceCount; i++)
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{
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const Candidate & candidate = getBestCandidate();
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if (candidate.metric > threshold) {
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return false; // Can't grow more.
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}
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addFaceToChart(candidate.chart, candidate.face);
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}
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return facesLeft != 0; // Can continue growing.
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#else // Using one list per chart.
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bool canGrowMore = false;
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const uint chartCount = chartArray.count();
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for (uint i = 0; i < chartCount; i++)
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{
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if (growChart(chartArray[i], threshold, faceCount))
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{
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canGrowMore = true;
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}
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}
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return canGrowMore;
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#endif
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}
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bool AtlasBuilder::growChart(ChartBuildData * chart, float threshold, uint faceCount)
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{
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// Try to add faceCount faces within threshold to chart.
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for (uint i = 0; i < faceCount; )
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{
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if (chart->candidates.count() == 0 || chart->candidates.firstPriority() > threshold)
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{
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return false;
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}
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uint f = chart->candidates.pop();
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if (faceChartArray[f] == -1)
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{
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addFaceToChart(chart, f);
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i++;
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}
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}
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if (chart->candidates.count() == 0 || chart->candidates.firstPriority() > threshold)
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{
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return false;
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}
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return true;
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}
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void AtlasBuilder::resetCharts()
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{
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const uint faceCount = mesh->faceCount();
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for (uint i = 0; i < faceCount; i++)
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{
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faceChartArray[i] = -1;
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faceCandidateArray[i] = -1;
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}
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facesLeft = faceCount;
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candidateArray.clear();
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const uint chartCount = chartArray.count();
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for (uint i = 0; i < chartCount; i++)
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{
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ChartBuildData * chart = chartArray[i];
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const uint seed = chart->seeds.back();
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chart->area = 0.0f;
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||
|
|
chart->boundaryLength = 0.0f;
|
||
|
|
chart->normalSum = Vector3(0);
|
||
|
|
chart->centroidSum = Vector3(0);
|
||
|
|
|
||
|
|
chart->faces.clear();
|
||
|
|
chart->candidates.clear();
|
||
|
|
|
||
|
|
addFaceToChart(chart, seed);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
void AtlasBuilder::updateCandidates(ChartBuildData * chart, uint f)
|
||
|
|
{
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(f);
|
||
|
|
|
||
|
|
// Traverse neighboring faces, add the ones that do not belong to any chart yet.
|
||
|
|
for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance())
|
||
|
|
{
|
||
|
|
const HalfEdge::Edge * edge = it.current()->pair;
|
||
|
|
|
||
|
|
if (!edge->isBoundary())
|
||
|
|
{
|
||
|
|
uint f = edge->face->id;
|
||
|
|
|
||
|
|
if (faceChartArray[f] == -1)
|
||
|
|
{
|
||
|
|
chart->candidates.push(f);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
void AtlasBuilder::updateProxies()
|
||
|
|
{
|
||
|
|
const uint chartCount = chartArray.count();
|
||
|
|
for (uint i = 0; i < chartCount; i++)
|
||
|
|
{
|
||
|
|
updateProxy(chartArray[i]);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
namespace {
|
||
|
|
|
||
|
|
float absoluteSum(Vector4::Arg v)
|
||
|
|
{
|
||
|
|
return fabs(v.x) + fabs(v.y) + fabs(v.z) + fabs(v.w);
|
||
|
|
}
|
||
|
|
|
||
|
|
//#pragma message(NV_FILE_LINE "FIXME: Using the c=cos(teta) substitution, the equation system becomes linear and we can avoid the newton solver.")
|
||
|
|
|
||
|
|
struct ConeFitting
|
||
|
|
{
|
||
|
|
ConeFitting(const HalfEdge::Mesh * m, float g, float tf, float tx) : mesh(m), gamma(g), tolf(tf), tolx(tx), F(0), D(0), H(0) {
|
||
|
|
}
|
||
|
|
|
||
|
|
void addTerm(Vector3 N, float A)
|
||
|
|
{
|
||
|
|
const float c = cosf(X.w);
|
||
|
|
const float s = sinf(X.w);
|
||
|
|
const float tmp = dot(X.xyz(), N) - c;
|
||
|
|
|
||
|
|
F += tmp * tmp;
|
||
|
|
|
||
|
|
D.x += 2 * X.x * tmp;
|
||
|
|
D.y += 2 * X.y * tmp;
|
||
|
|
D.z += 2 * X.z * tmp;
|
||
|
|
D.w += 2 * s * tmp;
|
||
|
|
|
||
|
|
H(0,0) = 2 * X.x * N.x + 2 * tmp;
|
||
|
|
H(0,1) = 2 * X.x * N.y;
|
||
|
|
H(0,2) = 2 * X.x * N.z;
|
||
|
|
H(0,3) = 2 * X.x * s;
|
||
|
|
|
||
|
|
H(1,0) = 2 * X.y * N.x;
|
||
|
|
H(1,1) = 2 * X.y * N.y + 2 * tmp;
|
||
|
|
H(1,2) = 2 * X.y * N.z;
|
||
|
|
H(1,3) = 2 * X.y * s;
|
||
|
|
|
||
|
|
H(2,0) = 2 * X.z * N.x;
|
||
|
|
H(2,1) = 2 * X.z * N.y;
|
||
|
|
H(2,2) = 2 * X.z * N.z + 2 * tmp;
|
||
|
|
H(2,3) = 2 * X.z * s;
|
||
|
|
|
||
|
|
H(3,0) = 2 * s * N.x;
|
||
|
|
H(3,1) = 2 * s * N.y;
|
||
|
|
H(3,2) = 2 * s * N.z;
|
||
|
|
H(3,3) = 2 * s * s + 2 * c * tmp;
|
||
|
|
}
|
||
|
|
|
||
|
|
Vector4 solve(ChartBuildData * chart, Vector4 start)
|
||
|
|
{
|
||
|
|
const uint faceCount = chart->faces.count();
|
||
|
|
|
||
|
|
X = start;
|
||
|
|
|
||
|
|
Vector4 dX;
|
||
|
|
|
||
|
|
do {
|
||
|
|
for (uint i = 0; i < faceCount; i++)
|
||
|
|
{
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(chart->faces[i]);
|
||
|
|
|
||
|
|
addTerm(face->normal(), face->area());
|
||
|
|
}
|
||
|
|
|
||
|
|
Vector4 dX;
|
||
|
|
//solveKramer(H, D, &dX);
|
||
|
|
solveLU(H, D, &dX);
|
||
|
|
|
||
|
|
// @@ Do a full newton step and reduce by half if F doesn't decrease.
|
||
|
|
X -= gamma * dX;
|
||
|
|
|
||
|
|
// Constrain normal to be normalized.
|
||
|
|
X = Vector4(normalize(X.xyz()), X.w);
|
||
|
|
|
||
|
|
} while(absoluteSum(D) > tolf || absoluteSum(dX) > tolx);
|
||
|
|
|
||
|
|
return X;
|
||
|
|
}
|
||
|
|
|
||
|
|
HalfEdge::Mesh const * const mesh;
|
||
|
|
const float gamma;
|
||
|
|
const float tolf;
|
||
|
|
const float tolx;
|
||
|
|
|
||
|
|
Vector4 X;
|
||
|
|
|
||
|
|
float F;
|
||
|
|
Vector4 D;
|
||
|
|
Matrix H;
|
||
|
|
};
|
||
|
|
|
||
|
|
// Unnormalized face normal assuming it's a triangle.
|
||
|
|
static Vector3 triangleNormal(const HalfEdge::Face * face)
|
||
|
|
{
|
||
|
|
Vector3 p0 = face->edge->vertex->pos;
|
||
|
|
Vector3 p1 = face->edge->next->vertex->pos;
|
||
|
|
Vector3 p2 = face->edge->next->next->vertex->pos;
|
||
|
|
|
||
|
|
Vector3 e0 = p2 - p0;
|
||
|
|
Vector3 e1 = p1 - p0;
|
||
|
|
|
||
|
|
return normalizeSafe(cross(e0, e1), Vector3(0), 0.0f);
|
||
|
|
}
|
||
|
|
|
||
|
|
static Vector3 triangleNormalAreaScaled(const HalfEdge::Face * face)
|
||
|
|
{
|
||
|
|
Vector3 p0 = face->edge->vertex->pos;
|
||
|
|
Vector3 p1 = face->edge->next->vertex->pos;
|
||
|
|
Vector3 p2 = face->edge->next->next->vertex->pos;
|
||
|
|
|
||
|
|
Vector3 e0 = p2 - p0;
|
||
|
|
Vector3 e1 = p1 - p0;
|
||
|
|
|
||
|
|
return cross(e0, e1);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Average of the edge midpoints weighted by the edge length.
|
||
|
|
// I want a point inside the triangle, but closer to the cirumcenter.
|
||
|
|
static Vector3 triangleCenter(const HalfEdge::Face * face)
|
||
|
|
{
|
||
|
|
Vector3 p0 = face->edge->vertex->pos;
|
||
|
|
Vector3 p1 = face->edge->next->vertex->pos;
|
||
|
|
Vector3 p2 = face->edge->next->next->vertex->pos;
|
||
|
|
|
||
|
|
float l0 = length(p1 - p0);
|
||
|
|
float l1 = length(p2 - p1);
|
||
|
|
float l2 = length(p0 - p2);
|
||
|
|
|
||
|
|
Vector3 m0 = (p0 + p1) * l0 / (l0 + l1 + l2);
|
||
|
|
Vector3 m1 = (p1 + p2) * l1 / (l0 + l1 + l2);
|
||
|
|
Vector3 m2 = (p2 + p0) * l2 / (l0 + l1 + l2);
|
||
|
|
|
||
|
|
return m0 + m1 + m2;
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace
|
||
|
|
|
||
|
|
void AtlasBuilder::updateProxy(ChartBuildData * chart)
|
||
|
|
{
|
||
|
|
//#pragma message(NV_FILE_LINE "TODO: Use best fit plane instead of average normal.")
|
||
|
|
|
||
|
|
chart->planeNormal = normalizeSafe(chart->normalSum, Vector3(0), 0.0f);
|
||
|
|
chart->centroid = chart->centroidSum / float(chart->faces.count());
|
||
|
|
|
||
|
|
//#pragma message(NV_FILE_LINE "TODO: Experiment with conic fitting.")
|
||
|
|
|
||
|
|
// F = (Nc*Nt - cos Oc)^2 = (x*Nt_x + y*Nt_y + z*Nt_z - cos w)^2
|
||
|
|
// dF/dx = 2 * x * (x*Nt_x + y*Nt_y + z*Nt_z - cos w)
|
||
|
|
// dF/dy = 2 * y * (x*Nt_x + y*Nt_y + z*Nt_z - cos w)
|
||
|
|
// dF/dz = 2 * z * (x*Nt_x + y*Nt_y + z*Nt_z - cos w)
|
||
|
|
// dF/dw = 2 * sin w * (x*Nt_x + y*Nt_y + z*Nt_z - cos w)
|
||
|
|
|
||
|
|
// JacobianMatrix({
|
||
|
|
// 2 * x * (x*Nt_x + y*Nt_y + z*Nt_z - Cos(w)),
|
||
|
|
// 2 * y * (x*Nt_x + y*Nt_y + z*Nt_z - Cos(w)),
|
||
|
|
// 2 * z * (x*Nt_x + y*Nt_y + z*Nt_z - Cos(w)),
|
||
|
|
// 2 * Sin(w) * (x*Nt_x + y*Nt_y + z*Nt_z - Cos(w))}, {x,y,z,w})
|
||
|
|
|
||
|
|
// H[0,0] = 2 * x * Nt_x + 2 * (x*Nt_x + y*Nt_y + z*Nt_z - cos(w));
|
||
|
|
// H[0,1] = 2 * x * Nt_y;
|
||
|
|
// H[0,2] = 2 * x * Nt_z;
|
||
|
|
// H[0,3] = 2 * x * sin(w);
|
||
|
|
|
||
|
|
// H[1,0] = 2 * y * Nt_x;
|
||
|
|
// H[1,1] = 2 * y * Nt_y + 2 * (x*Nt_x + y*Nt_y + z*Nt_z - cos(w));
|
||
|
|
// H[1,2] = 2 * y * Nt_z;
|
||
|
|
// H[1,3] = 2 * y * sin(w);
|
||
|
|
|
||
|
|
// H[2,0] = 2 * z * Nt_x;
|
||
|
|
// H[2,1] = 2 * z * Nt_y;
|
||
|
|
// H[2,2] = 2 * z * Nt_z + 2 * (x*Nt_x + y*Nt_y + z*Nt_z - cos(w));
|
||
|
|
// H[2,3] = 2 * z * sin(w);
|
||
|
|
|
||
|
|
// H[3,0] = 2 * sin(w) * Nt_x;
|
||
|
|
// H[3,1] = 2 * sin(w) * Nt_y;
|
||
|
|
// H[3,2] = 2 * sin(w) * Nt_z;
|
||
|
|
// H[3,3] = 2 * sin(w) * sin(w) + 2 * cos(w) * (x*Nt_x + y*Nt_y + z*Nt_z - cos(w));
|
||
|
|
|
||
|
|
// @@ Cone fitting might be quite slow.
|
||
|
|
|
||
|
|
/*ConeFitting coneFitting(mesh, 0.1f, 0.001f, 0.001f);
|
||
|
|
|
||
|
|
Vector4 start = Vector4(chart->coneAxis, chart->coneAngle);
|
||
|
|
Vector4 solution = coneFitting.solve(chart, start);
|
||
|
|
|
||
|
|
chart->coneAxis = solution.xyz();
|
||
|
|
chart->coneAngle = solution.w;*/
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
bool AtlasBuilder::relocateSeeds()
|
||
|
|
{
|
||
|
|
bool anySeedChanged = false;
|
||
|
|
|
||
|
|
const uint chartCount = chartArray.count();
|
||
|
|
for (uint i = 0; i < chartCount; i++)
|
||
|
|
{
|
||
|
|
if (relocateSeed(chartArray[i]))
|
||
|
|
{
|
||
|
|
anySeedChanged = true;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return anySeedChanged;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
bool AtlasBuilder::relocateSeed(ChartBuildData * chart)
|
||
|
|
{
|
||
|
|
Vector3 centroid = computeChartCentroid(chart);
|
||
|
|
|
||
|
|
const uint N = 10; // @@ Hardcoded to 10?
|
||
|
|
PriorityQueue bestTriangles(N);
|
||
|
|
|
||
|
|
// Find the first N triangles that fit the proxy best.
|
||
|
|
const uint faceCount = chart->faces.count();
|
||
|
|
for (uint i = 0; i < faceCount; i++)
|
||
|
|
{
|
||
|
|
float priority = evaluateProxyFitMetric(chart, chart->faces[i]);
|
||
|
|
bestTriangles.push(priority, chart->faces[i]);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Of those, choose the most central triangle.
|
||
|
|
uint mostCentral;
|
||
|
|
float maxDistance = -1;
|
||
|
|
|
||
|
|
const uint bestCount = bestTriangles.count();
|
||
|
|
for (uint i = 0; i < bestCount; i++)
|
||
|
|
{
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(bestTriangles.pairs[i].face);
|
||
|
|
Vector3 faceCentroid = triangleCenter(face);
|
||
|
|
|
||
|
|
float distance = length(centroid - faceCentroid);
|
||
|
|
|
||
|
|
/*#pragma message(NV_FILE_LINE "TODO: Implement evaluateDistanceToBoundary.")
|
||
|
|
float distance = evaluateDistanceToBoundary(chart, bestTriangles.pairs[i].face);*/
|
||
|
|
|
||
|
|
if (distance > maxDistance)
|
||
|
|
{
|
||
|
|
maxDistance = distance;
|
||
|
|
mostCentral = bestTriangles.pairs[i].face;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
nvDebugCheck(maxDistance >= 0);
|
||
|
|
|
||
|
|
// In order to prevent k-means cyles we record all the previously chosen seeds.
|
||
|
|
uint index;
|
||
|
|
if (chart->seeds.find(mostCentral, &index))
|
||
|
|
{
|
||
|
|
// Move new seed to the end of the seed array.
|
||
|
|
uint last = chart->seeds.count() - 1;
|
||
|
|
swap(chart->seeds[index], chart->seeds[last]);
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
// Append new seed.
|
||
|
|
chart->seeds.append(mostCentral);
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void AtlasBuilder::removeCandidate(uint f)
|
||
|
|
{
|
||
|
|
int c = faceCandidateArray[f];
|
||
|
|
if (c != -1) {
|
||
|
|
faceCandidateArray[f] = -1;
|
||
|
|
|
||
|
|
if (c == candidateArray.count() - 1) {
|
||
|
|
candidateArray.popBack();
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
candidateArray.replaceWithLast(c);
|
||
|
|
faceCandidateArray[candidateArray[c].face] = c;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void AtlasBuilder::updateCandidate(ChartBuildData * chart, uint f, float metric)
|
||
|
|
{
|
||
|
|
if (faceCandidateArray[f] == -1) {
|
||
|
|
const uint index = candidateArray.count();
|
||
|
|
faceCandidateArray[f] = index;
|
||
|
|
candidateArray.resize(index + 1);
|
||
|
|
candidateArray[index].face = f;
|
||
|
|
candidateArray[index].chart = chart;
|
||
|
|
candidateArray[index].metric = metric;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
int c = faceCandidateArray[f];
|
||
|
|
nvDebugCheck(c != -1);
|
||
|
|
|
||
|
|
Candidate & candidate = candidateArray[c];
|
||
|
|
nvDebugCheck(candidate.face == f);
|
||
|
|
|
||
|
|
if (metric < candidate.metric || chart == candidate.chart) {
|
||
|
|
candidate.metric = metric;
|
||
|
|
candidate.chart = chart;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
void AtlasBuilder::updatePriorities(ChartBuildData * chart)
|
||
|
|
{
|
||
|
|
// Re-evaluate candidate priorities.
|
||
|
|
uint candidateCount = chart->candidates.count();
|
||
|
|
for (uint i = 0; i < candidateCount; i++)
|
||
|
|
{
|
||
|
|
chart->candidates.pairs[i].priority = evaluatePriority(chart, chart->candidates.pairs[i].face);
|
||
|
|
|
||
|
|
if (faceChartArray[chart->candidates.pairs[i].face] == -1)
|
||
|
|
{
|
||
|
|
updateCandidate(chart, chart->candidates.pairs[i].face, chart->candidates.pairs[i].priority);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Sort candidates.
|
||
|
|
chart->candidates.sort();
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
// Evaluate combined metric.
|
||
|
|
float AtlasBuilder::evaluatePriority(ChartBuildData * chart, uint face)
|
||
|
|
{
|
||
|
|
// Estimate boundary length and area:
|
||
|
|
float newBoundaryLength = evaluateBoundaryLength(chart, face);
|
||
|
|
float newChartArea = evaluateChartArea(chart, face);
|
||
|
|
|
||
|
|
float F = evaluateProxyFitMetric(chart, face);
|
||
|
|
float C = evaluateRoundnessMetric(chart, face, newBoundaryLength, newChartArea);
|
||
|
|
float P = evaluateStraightnessMetric(chart, face);
|
||
|
|
|
||
|
|
// Penalize faces that cross seams, reward faces that close seams or reach boundaries.
|
||
|
|
float N = evaluateNormalSeamMetric(chart, face);
|
||
|
|
float T = evaluateTextureSeamMetric(chart, face);
|
||
|
|
|
||
|
|
//float R = evaluateCompletenessMetric(chart, face);
|
||
|
|
|
||
|
|
//float D = evaluateDihedralAngleMetric(chart, face);
|
||
|
|
// @@ Add a metric based on local dihedral angle.
|
||
|
|
|
||
|
|
// @@ Tweaking the normal and texture seam metrics.
|
||
|
|
// - Cause more impedance. Never cross 90 degree edges.
|
||
|
|
// -
|
||
|
|
|
||
|
|
float cost = float(
|
||
|
|
settings.proxyFitMetricWeight * F +
|
||
|
|
settings.roundnessMetricWeight * C +
|
||
|
|
settings.straightnessMetricWeight * P +
|
||
|
|
settings.normalSeamMetricWeight * N +
|
||
|
|
settings.textureSeamMetricWeight * T);
|
||
|
|
|
||
|
|
/*cost = settings.proxyFitMetricWeight * powf(F, settings.proxyFitMetricExponent);
|
||
|
|
cost = max(cost, settings.roundnessMetricWeight * powf(C, settings.roundnessMetricExponent));
|
||
|
|
cost = max(cost, settings.straightnessMetricWeight * pow(P, settings.straightnessMetricExponent));
|
||
|
|
cost = max(cost, settings.normalSeamMetricWeight * N);
|
||
|
|
cost = max(cost, settings.textureSeamMetricWeight * T);*/
|
||
|
|
|
||
|
|
// Enforce limits strictly:
|
||
|
|
if (newChartArea > settings.maxChartArea) cost = FLT_MAX;
|
||
|
|
if (newBoundaryLength > settings.maxBoundaryLength) cost = FLT_MAX;
|
||
|
|
|
||
|
|
// Make sure normal seams are fully respected:
|
||
|
|
if (settings.normalSeamMetricWeight >= 1000 && N != 0) cost = FLT_MAX;
|
||
|
|
|
||
|
|
nvCheck(isFinite(cost));
|
||
|
|
return cost;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
// Returns a value in [0-1].
|
||
|
|
float AtlasBuilder::evaluateProxyFitMetric(ChartBuildData * chart, uint f)
|
||
|
|
{
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(f);
|
||
|
|
Vector3 faceNormal = triangleNormal(face);
|
||
|
|
//return square(dot(chart->coneAxis, faceNormal) - cosf(chart->coneAngle));
|
||
|
|
|
||
|
|
// Use plane fitting metric for now:
|
||
|
|
//return square(1 - dot(faceNormal, chart->planeNormal)); // @@ normal deviations should be weighted by face area
|
||
|
|
return 1 - dot(faceNormal, chart->planeNormal); // @@ normal deviations should be weighted by face area
|
||
|
|
|
||
|
|
// Find distance to chart.
|
||
|
|
/*Vector3 faceCentroid = face->centroid();
|
||
|
|
|
||
|
|
float dist = 0;
|
||
|
|
int count = 0;
|
||
|
|
|
||
|
|
for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance())
|
||
|
|
{
|
||
|
|
const HalfEdge::Edge * edge = it.current();
|
||
|
|
|
||
|
|
if (!edge->isBoundary()) {
|
||
|
|
const HalfEdge::Face * neighborFace = edge->pair()->face();
|
||
|
|
if (faceChartArray[neighborFace->id()] == chart->id) {
|
||
|
|
dist += length(neighborFace->centroid() - faceCentroid);
|
||
|
|
count++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
dist /= (count * count);
|
||
|
|
|
||
|
|
return (1 - dot(faceNormal, chart->planeNormal)) * dist;*/
|
||
|
|
|
||
|
|
//return (1 - dot(faceNormal, chart->planeNormal));
|
||
|
|
}
|
||
|
|
|
||
|
|
float AtlasBuilder::evaluateDistanceToBoundary(ChartBuildData * chart, uint face)
|
||
|
|
{
|
||
|
|
//#pragma message(NV_FILE_LINE "TODO: Evaluate distance to boundary metric.")
|
||
|
|
|
||
|
|
// @@ This is needed for the seed relocation code.
|
||
|
|
// @@ This could provide a better roundness metric.
|
||
|
|
|
||
|
|
return 0.0f;
|
||
|
|
}
|
||
|
|
|
||
|
|
float AtlasBuilder::evaluateDistanceToSeed(ChartBuildData * chart, uint f)
|
||
|
|
{
|
||
|
|
//const uint seed = chart->seeds.back();
|
||
|
|
//const uint faceCount = mesh->faceCount();
|
||
|
|
//return shortestPaths[seed * faceCount + f];
|
||
|
|
|
||
|
|
const HalfEdge::Face * seed = mesh->faceAt(chart->seeds.back());
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(f);
|
||
|
|
return length(triangleCenter(seed) - triangleCenter(face));
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
float AtlasBuilder::evaluateRoundnessMetric(ChartBuildData * chart, uint face, float newBoundaryLength, float newChartArea)
|
||
|
|
{
|
||
|
|
// @@ D-charts use distance to seed.
|
||
|
|
// C(c,t) = pi * D(S_c,t)^2 / A_c
|
||
|
|
//return PI * square(evaluateDistanceToSeed(chart, face)) / chart->area;
|
||
|
|
//return PI * square(evaluateDistanceToSeed(chart, face)) / chart->area;
|
||
|
|
//return 2 * PI * evaluateDistanceToSeed(chart, face) / chart->boundaryLength;
|
||
|
|
|
||
|
|
// Garland's Hierarchical Face Clustering paper uses ratio between boundary and area, which is easier to compute and might work as well:
|
||
|
|
// roundness = D^2/4*pi*A -> circle = 1, non circle greater than 1
|
||
|
|
|
||
|
|
//return square(newBoundaryLength) / (newChartArea * 4 * PI);
|
||
|
|
float roundness = square(chart->boundaryLength) / chart->area;
|
||
|
|
float newRoundness = square(newBoundaryLength) / newChartArea;
|
||
|
|
if (newRoundness > roundness) {
|
||
|
|
return square(newBoundaryLength) / (newChartArea * 4 * PI);
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
// Offer no impedance to faces that improve roundness.
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
//return square(newBoundaryLength) / (4 * PI * newChartArea);
|
||
|
|
//return clamp(1 - (4 * PI * newChartArea) / square(newBoundaryLength), 0.0f, 1.0f);
|
||
|
|
|
||
|
|
// Use the ratio between the new roundness vs. the previous roundness.
|
||
|
|
// - If we use the absolute metric, when the initial face is very long, then it's hard to make any progress.
|
||
|
|
//return (square(newBoundaryLength) * chart->area) / (square(chart->boundaryLength) * newChartArea);
|
||
|
|
//return (4 * PI * newChartArea) / square(newBoundaryLength) - (4 * PI * chart->area) / square(chart->boundaryLength);
|
||
|
|
|
||
|
|
//if (square(newBoundaryLength) * chart->area) / (square(chart->boundaryLength) * newChartArea);
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
float AtlasBuilder::evaluateStraightnessMetric(ChartBuildData * chart, uint f)
|
||
|
|
{
|
||
|
|
float l_out = 0.0f;
|
||
|
|
float l_in = 0.0f;
|
||
|
|
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(f);
|
||
|
|
for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance())
|
||
|
|
{
|
||
|
|
const HalfEdge::Edge * edge = it.current();
|
||
|
|
|
||
|
|
//float l = edge->length();
|
||
|
|
float l = edgeLengths[edge->id/2];
|
||
|
|
|
||
|
|
if (edge->isBoundary())
|
||
|
|
{
|
||
|
|
l_out += l;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
uint neighborFaceId = edge->pair->face->id;
|
||
|
|
if (faceChartArray[neighborFaceId] != chart->id) {
|
||
|
|
l_out += l;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
l_in += l;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
nvDebugCheck(l_in != 0.0f); // Candidate face must be adjacent to chart. @@ This is not true if the input mesh has zero-length edges.
|
||
|
|
|
||
|
|
//return l_out / l_in;
|
||
|
|
float ratio = (l_out - l_in) / (l_out + l_in);
|
||
|
|
//if (ratio < 0) ratio *= 10; // Encourage closing gaps.
|
||
|
|
return min(ratio, 0.0f); // Only use the straightness metric to close gaps.
|
||
|
|
//return ratio;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
float AtlasBuilder::evaluateNormalSeamMetric(ChartBuildData * chart, uint f)
|
||
|
|
{
|
||
|
|
float seamFactor = 0.0f;
|
||
|
|
float totalLength = 0.0f;
|
||
|
|
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(f);
|
||
|
|
for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance())
|
||
|
|
{
|
||
|
|
const HalfEdge::Edge * edge = it.current();
|
||
|
|
|
||
|
|
if (edge->isBoundary()) {
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
const uint neighborFaceId = edge->pair->face->id;
|
||
|
|
if (faceChartArray[neighborFaceId] != chart->id) {
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
//float l = edge->length();
|
||
|
|
float l = edgeLengths[edge->id/2];
|
||
|
|
|
||
|
|
totalLength += l;
|
||
|
|
|
||
|
|
if (!edge->isSeam()) {
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Make sure it's a normal seam.
|
||
|
|
if (isNormalSeam(edge))
|
||
|
|
{
|
||
|
|
float d0 = clamp(dot(edge->vertex->nor, edge->pair->next->vertex->nor), 0.0f, 1.0f);
|
||
|
|
float d1 = clamp(dot(edge->next->vertex->nor, edge->pair->vertex->nor), 0.0f, 1.0f);
|
||
|
|
//float a0 = clamp(acosf(d0) / (PI/2), 0.0f, 1.0f);
|
||
|
|
//float a1 = clamp(acosf(d1) / (PI/2), 0.0f, 1.0f);
|
||
|
|
//l *= (a0 + a1) * 0.5f;
|
||
|
|
|
||
|
|
l *= 1 - (d0 + d1) * 0.5f;
|
||
|
|
|
||
|
|
seamFactor += l;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (seamFactor == 0) return 0.0f;
|
||
|
|
return seamFactor / totalLength;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
float AtlasBuilder::evaluateTextureSeamMetric(ChartBuildData * chart, uint f)
|
||
|
|
{
|
||
|
|
float seamLength = 0.0f;
|
||
|
|
//float newSeamLength = 0.0f;
|
||
|
|
//float oldSeamLength = 0.0f;
|
||
|
|
float totalLength = 0.0f;
|
||
|
|
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(f);
|
||
|
|
for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance())
|
||
|
|
{
|
||
|
|
const HalfEdge::Edge * edge = it.current();
|
||
|
|
|
||
|
|
/*float l = edge->length();
|
||
|
|
totalLength += l;
|
||
|
|
|
||
|
|
if (edge->isBoundary() || !edge->isSeam()) {
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Make sure it's a texture seam.
|
||
|
|
if (isTextureSeam(edge))
|
||
|
|
{
|
||
|
|
uint neighborFaceId = edge->pair()->face()->id();
|
||
|
|
if (faceChartArray[neighborFaceId] != chart->id) {
|
||
|
|
newSeamLength += l;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
oldSeamLength += l;
|
||
|
|
}
|
||
|
|
}*/
|
||
|
|
|
||
|
|
if (edge->isBoundary()) {
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
const uint neighborFaceId = edge->pair->face->id;
|
||
|
|
if (faceChartArray[neighborFaceId] != chart->id) {
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
//float l = edge->length();
|
||
|
|
float l = edgeLengths[edge->id/2];
|
||
|
|
totalLength += l;
|
||
|
|
|
||
|
|
if (!edge->isSeam()) {
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Make sure it's a texture seam.
|
||
|
|
if (isTextureSeam(edge))
|
||
|
|
{
|
||
|
|
seamLength += l;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (seamLength == 0.0f) {
|
||
|
|
return 0.0f; // Avoid division by zero.
|
||
|
|
}
|
||
|
|
|
||
|
|
return seamLength / totalLength;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
float AtlasBuilder::evaluateSeamMetric(ChartBuildData * chart, uint f)
|
||
|
|
{
|
||
|
|
float newSeamLength = 0.0f;
|
||
|
|
float oldSeamLength = 0.0f;
|
||
|
|
float totalLength = 0.0f;
|
||
|
|
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(f);
|
||
|
|
for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance())
|
||
|
|
{
|
||
|
|
const HalfEdge::Edge * edge = it.current();
|
||
|
|
|
||
|
|
//float l = edge->length();
|
||
|
|
float l = edgeLengths[edge->id/2];
|
||
|
|
|
||
|
|
if (edge->isBoundary())
|
||
|
|
{
|
||
|
|
newSeamLength += l;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
if (edge->isSeam())
|
||
|
|
{
|
||
|
|
uint neighborFaceId = edge->pair->face->id;
|
||
|
|
if (faceChartArray[neighborFaceId] != chart->id) {
|
||
|
|
newSeamLength += l;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
oldSeamLength += l;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
totalLength += l;
|
||
|
|
}
|
||
|
|
|
||
|
|
return (newSeamLength - oldSeamLength) / totalLength;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
float AtlasBuilder::evaluateChartArea(ChartBuildData * chart, uint f)
|
||
|
|
{
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(f);
|
||
|
|
//return chart->area + face->area();
|
||
|
|
return chart->area + faceAreas[face->id];
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
float AtlasBuilder::evaluateBoundaryLength(ChartBuildData * chart, uint f)
|
||
|
|
{
|
||
|
|
float boundaryLength = chart->boundaryLength;
|
||
|
|
|
||
|
|
// Add new edges, subtract edges shared with the chart.
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(f);
|
||
|
|
for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance())
|
||
|
|
{
|
||
|
|
const HalfEdge::Edge * edge = it.current();
|
||
|
|
//float edgeLength = edge->length();
|
||
|
|
float edgeLength = edgeLengths[edge->id/2];
|
||
|
|
|
||
|
|
if (edge->isBoundary())
|
||
|
|
{
|
||
|
|
boundaryLength += edgeLength;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
uint neighborFaceId = edge->pair->face->id;
|
||
|
|
if (faceChartArray[neighborFaceId] != chart->id) {
|
||
|
|
boundaryLength += edgeLength;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
boundaryLength -= edgeLength;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
//nvDebugCheck(boundaryLength >= 0);
|
||
|
|
|
||
|
|
return max(0.0f, boundaryLength); // @@ Hack!
|
||
|
|
}
|
||
|
|
|
||
|
|
Vector3 AtlasBuilder::evaluateChartNormalSum(ChartBuildData * chart, uint f)
|
||
|
|
{
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(f);
|
||
|
|
return chart->normalSum + triangleNormalAreaScaled(face);
|
||
|
|
}
|
||
|
|
|
||
|
|
Vector3 AtlasBuilder::evaluateChartCentroidSum(ChartBuildData * chart, uint f)
|
||
|
|
{
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(f);
|
||
|
|
return chart->centroidSum + face->centroid();
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
Vector3 AtlasBuilder::computeChartCentroid(const ChartBuildData * chart)
|
||
|
|
{
|
||
|
|
Vector3 centroid(0);
|
||
|
|
|
||
|
|
const uint faceCount = chart->faces.count();
|
||
|
|
for (uint i = 0; i < faceCount; i++)
|
||
|
|
{
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(chart->faces[i]);
|
||
|
|
centroid += triangleCenter(face);
|
||
|
|
}
|
||
|
|
|
||
|
|
return centroid / float(faceCount);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
void AtlasBuilder::fillHoles(float threshold)
|
||
|
|
{
|
||
|
|
while (facesLeft > 0)
|
||
|
|
{
|
||
|
|
createRandomChart(threshold);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
void AtlasBuilder::mergeChart(ChartBuildData * owner, ChartBuildData * chart, float sharedBoundaryLength)
|
||
|
|
{
|
||
|
|
const uint faceCount = chart->faces.count();
|
||
|
|
for (uint i = 0; i < faceCount; i++)
|
||
|
|
{
|
||
|
|
uint f = chart->faces[i];
|
||
|
|
|
||
|
|
nvDebugCheck(faceChartArray[f] == chart->id);
|
||
|
|
faceChartArray[f] = owner->id;
|
||
|
|
|
||
|
|
owner->faces.append(f);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Update adjacencies?
|
||
|
|
|
||
|
|
owner->area += chart->area;
|
||
|
|
owner->boundaryLength += chart->boundaryLength - sharedBoundaryLength;
|
||
|
|
|
||
|
|
owner->normalSum += chart->normalSum;
|
||
|
|
owner->centroidSum += chart->centroidSum;
|
||
|
|
|
||
|
|
updateProxy(owner);
|
||
|
|
}
|
||
|
|
|
||
|
|
void AtlasBuilder::mergeCharts()
|
||
|
|
{
|
||
|
|
Array<float> sharedBoundaryLengths;
|
||
|
|
|
||
|
|
const uint chartCount = chartArray.count();
|
||
|
|
for (int c = chartCount-1; c >= 0; c--)
|
||
|
|
{
|
||
|
|
sharedBoundaryLengths.clear();
|
||
|
|
sharedBoundaryLengths.resize(chartCount, 0.0f);
|
||
|
|
|
||
|
|
ChartBuildData * chart = chartArray[c];
|
||
|
|
|
||
|
|
float externalBoundary = 0.0f;
|
||
|
|
|
||
|
|
const uint faceCount = chart->faces.count();
|
||
|
|
for (uint i = 0; i < faceCount; i++)
|
||
|
|
{
|
||
|
|
uint f = chart->faces[i];
|
||
|
|
const HalfEdge::Face * face = mesh->faceAt(f);
|
||
|
|
|
||
|
|
for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance())
|
||
|
|
{
|
||
|
|
const HalfEdge::Edge * edge = it.current();
|
||
|
|
|
||
|
|
//float l = edge->length();
|
||
|
|
float l = edgeLengths[edge->id/2];
|
||
|
|
|
||
|
|
if (edge->isBoundary()) {
|
||
|
|
externalBoundary += l;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
uint neighborFace = edge->pair->face->id;
|
||
|
|
uint neighborChart = faceChartArray[neighborFace];
|
||
|
|
|
||
|
|
if (neighborChart != c) {
|
||
|
|
if ((edge->isSeam() && (isNormalSeam(edge) || isTextureSeam(edge))) || neighborChart == -2) {
|
||
|
|
externalBoundary += l;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
sharedBoundaryLengths[neighborChart] += l;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int cc = chartCount-1; cc >= 0; cc--)
|
||
|
|
{
|
||
|
|
if (cc == c)
|
||
|
|
continue;
|
||
|
|
|
||
|
|
ChartBuildData * chart2 = chartArray[cc];
|
||
|
|
if (chart2 == NULL)
|
||
|
|
continue;
|
||
|
|
|
||
|
|
if (sharedBoundaryLengths[cc] > 0.8 * max(0.0f, chart->boundaryLength - externalBoundary)) {
|
||
|
|
|
||
|
|
// Try to avoid degenerate configurations.
|
||
|
|
if (chart2->boundaryLength > sharedBoundaryLengths[cc])
|
||
|
|
{
|
||
|
|
if (dot(chart2->planeNormal, chart->planeNormal) > -0.25) {
|
||
|
|
mergeChart(chart2, chart, sharedBoundaryLengths[cc]);
|
||
|
|
delete chart;
|
||
|
|
chartArray[c] = NULL;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (sharedBoundaryLengths[cc] > 0.20 * max(0.0f, chart->boundaryLength - externalBoundary)) {
|
||
|
|
|
||
|
|
// Compare proxies.
|
||
|
|
if (dot(chart2->planeNormal, chart->planeNormal) > 0) {
|
||
|
|
mergeChart(chart2, chart, sharedBoundaryLengths[cc]);
|
||
|
|
delete chart;
|
||
|
|
chartArray[c] = NULL;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Remove deleted charts.
|
||
|
|
for (int c = 0; c < I32(chartArray.count()); /*do not increment if removed*/)
|
||
|
|
{
|
||
|
|
if (chartArray[c] == NULL) {
|
||
|
|
chartArray.removeAt(c);
|
||
|
|
|
||
|
|
// Update faceChartArray.
|
||
|
|
const uint faceCount = faceChartArray.count();
|
||
|
|
for (uint i = 0; i < faceCount; i++) {
|
||
|
|
nvDebugCheck (faceChartArray[i] != -1);
|
||
|
|
nvDebugCheck (faceChartArray[i] != c);
|
||
|
|
nvDebugCheck (faceChartArray[i] <= I32(chartArray.count()));
|
||
|
|
|
||
|
|
if (faceChartArray[i] > c) {
|
||
|
|
faceChartArray[i]--;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
chartArray[c]->id = c;
|
||
|
|
c++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
const Array<uint> & AtlasBuilder::chartFaces(uint i) const
|
||
|
|
{
|
||
|
|
return chartArray[i]->faces;
|
||
|
|
}
|